Week 6 Improving Decision Making and
Managing Knowledge
10.3 Intelligent Systems for Decision Support
10.4 Systems for Managing Knowledge
10.3 Intelligent Systems for Decision Support
• A number of intelligent techniques for enhancing decision making are based on Artificial intelligence (AI) technology.
• Artificial intelligence (AI) technology is consists of computer-based systems (both hardware and software) that attempt to emulate human behavior and thought patterns.
Artificial Intelligence (AI) Technology
• 1. Expert systems (ระบบผู้เชี่ยญชาญ)
• 2. Case-based reasoning (การให้เหตุผลด้วยฐานกรณี )
• 3. Fuzzy logic (ตรรกศาสตร์คลุมเครือ)
• 4. Neural networks (โครงข่ายประสาทเทียม)
• 5 . Genetic algorithms (อลักอลิทึมพันธุกรรม)
• 6 . Intelligent agents (ตัวแทนอัจฉริยะ)
1.EXPERT SYSTEMS
• What if employees in your firm had to make decisions that required some special knowledge, such as how to formulate a fast-drying sealing compound or how to diagnose and repair a malfunctioning diesel engine, but all the people with that expertise had left the firm?
• Expert systems are one type of decision-making aid that could help you out. An expert system captures human expertise in a limited domain of knowledge as a set of rules in a software system that can be used by others in the organization.
• These systems typically perform a limited number of tasks that can be performed by professionals in a few minutes or hours, such as diagnosing a malfunctioning machine or determining whether to grant credit for a loan.
• They are useful in decision-making situations where expertise is expensive or in short supply.
How Expert Systems Work
• Human knowledge must be modeled or represented in a form that a computer can process.
• Expert systems model human knowledge as a set of rules that collectively are called the knowledge base.
• Expert systems can have from 200 to as many as 10,000 of these rules, depending on the complexity of the decision-making problem.
• These rules are much more interconnected and nested than in a traditional software program (see Figure 10-8).
• The strategy used to search through the collection of rules and formulate conclusions is called the inference engine. The inference engine works by searching through the rules and “firing” those rules that are triggered by facts gathered and entered by the user.
• Expert systems provide businesses with an array of benefits, including improved decisions, reduced errors, reduced costs, reduced training time, and improved quality and service.
Figure 10-8 Rules in an Expert System
An expert system contains a set of rules to be followed when used. The rules are interconnected; the number of outcomes is known in advance and is limited; there are multiple paths to the same outcome; and the system can consider multiple rules at a single time. The rules illustrated are for a simple creditgranting expert system.
2.Case-based reasoning (CBR)
• Expert systems primarily capture the knowledge of individual experts, but organizations also have collective knowledge and expertise that they have built up over the years. This organizational knowledge can be captured and stored using case-based reasoning.
• In case-based reasoning(CBR), knowledge and past experiences of human specialists are represented as cases and stored in a database for later retrieval when the user encounters a new case with similar parameters. The system searches for stored cases with problem characteristics similar to the new one, finds the closest fit, and applies the solutions of the old case to the new case.
• Successful solutions are tagged to the new case and both are stored together with the other cases in the knowledge base. Unsuccessful solutions also are appended to the case database along with explanations as to why the solutions did not work (see Figure 10-9).
• You’ll find case-based reasoning in diagnostic systems in medicine or customer support where users can retrieve past cases whose characteristics are similar to the new case. The system suggests a solution or diagnosis based on the best-matching retrieved case.
Figure 10-9
How Case-Based Reasoning Works Case-based reasoning represents knowledge as a database of past cases and their solutions.
The system uses a six-step process to generate solutions to new problems encountered by the user.
3. Fuzzy logic
• Fuzzy logic is a rule-based technology that represents such imprecision by creating rules that use approximate or subjective values. It describes a particular phenomenon or process linguistically and then represents that description in a small number of flexible rules.
• Let’s look at the way fuzzy logic would represent various temperatures in a computer application to control room temperature automatically. The terms (known as membership functions) are imprecisely defined so that, for example, in Figure 10-10, cool is between 45 degrees and 70 degrees, although the temperature is most clearly cool between about 60 degrees and 67 degrees. Note that cool is overlapped by cold or norm. To control the room environment using this logic, the programmer would develop similarly imprecise definitions for humidity and other factors, such as outdoor wind and temperature. The rules might include one that says, “If the temperature is cool or cold and the humidity is low while the outdoor wind is high and the outdoor temperature is low, raise the heat and humidity in the room.” The computer would combine the membership function readings in a weighted manner and, using all the rules, raise and lower the temperature and humidity.
• Fuzzy logic provides solutions to problems requiring expertise that is difficult to represent in the form of crisp IF-THEN rules.
• In Japan, Sendai’s subway system uses fuzzy logic controls to accelerate so smoothly that standing passengers need not hold on.
• Fuzzy logic allows incremental changes in inputs to produce smooth changes in outputs instead of discontinuous ones, making it useful for consumer electronics and engineering applications
The membership functions for the input called temperature are in the logic of the thermostat to control the room temperature. Membership functions help translate linguistic expressions, such as warm, into numbers that the computer can manipulate
Figure 10-10 Fuzzy Logic for Temperature control
4.Neural networks
Neural networks are used for solving complex, poorly understood problems for which large amounts of data have been collected. They find patterns and relationships in massive amounts of data that would be too complicated and difficult for a human being to analyze.
Neural networks discover this knowledge by using hardware and software that parallel the processing patterns of the biological or human brain. Neural networks “learn” patterns from large quantities of data by sifting through data, searching for relationships, building models, and correcting over and over again the model’s own mistakes.
Figure 10-11 How a Neural Network Works
A neural network uses rules it “learns” from patterns in data to construct a hidden layer of logic.
The hidden layer then processes inputs, classifying them based on the experience of the model.
In this example, the neural network has been trained to distinguish between valid and fraudulent credit card purchases.
5.Genetic algorithms
• Genetic algorithms are useful for finding the optimal solution for a specific problem by examining a very large number of alternative solutions for that problem. They are based on techniques inspired by evolutionary biology, such as inheritance, mutation, selection, and crossover (recombination).
• A genetic algorithm works by representing a solution as a string of 0s and 1s. The genetic algorithm searches a population of randomly generated strings of binary digits to identify the right string representing the best possible solution for the problem. As solutions alter and combine, the worst ones are discarded and the better ones survive to go on to produce even better solutions.
• Genetic algorithms are used to solve complex problems that are very dynamic and complex, involving hundreds or thousands of variables or formulas. The problem must be one where the range of possible solutions can be represented genetically and criteria can be established for evaluating fitness.
• Genetic algorithms expedite the solution because they can evaluate many solution alternatives quickly to find the best one.
Figure 10-12 The Components of a Genetic Algorithm
This example illustrates an initial population of “chromosomes,” each representing a different solution.
The genetic algorithm uses an iterative process to refine the initial solutions so that the better ones, those with the higher fitness, are more likely to emerge as the best solution.
6. Intelligent agents
•Intelligent agent technology helps businesses and decision makers navigate through large amounts of data to locate and act on information that is considered important.
•Intelligent agents are software programs that work in the background without direct human intervention to carry out specific, repetitive, and predictable tasks for an individual user, business process, or software application.
•The agent uses a limited built-in or learned knowledge base to accomplish tasks or make decisions on the user’s behalf, such as deleting junk e-mail, scheduling appointments, or finding the cheapest airfare to California.
• There are many intelligent agent applications today in operating systems, application software, e-mail systems, mobile computing software, and network tools. Of special interest to busin